Carburetor heat deflector



April 21, 1953 D. BOYCE CARBURETOR HEAT DEFLECTOR INVENTOR. LEONARD D. BOYCE Filed Feb. 12. 1949 ATTORNEY FIG.2.

Patented Apr. 21, 1953 UNITED STATES PATENT OFFICE CARBURETOR HEAT DEFLECTOR Application February 12, 1949, Serial No. 76,008

1 Claim. 1

This invention relates to fuel feed means for internal combustion engines and consists particularly in novel means for shielding and deflecting engine heat therefrom.

Where a carburetor or other adjunct of the fuel system includes an accumulating or storage chamber for volatile fuel, engine heat sometimes affects the stored fuel so as to cause boiling or so-called percolation. Since this condition results most frequently just after stopping of a fully heated engine, it may delay restarting of the engine and it also may affect the accelerating pump 50 that an insufficient quantity of liquid fuel is supplied for the pick up charge.

It is the main object of the present invention to provide means for effectively shielding a fuel feed device, such as a carburetor, from engine heat.

A more detailed object is to provide such a heat shield which deflects engine heat from all sides as well as from beneath the device while permitting the escape of heat upwardly therefrom.

These objects and other more detailed objects are attained by the device and structure illustrated in the accompanying drawing in which Fig. 1 is a side view and vertical, transverse section illustrating an internal combustion engine carburetor having the invention applied thereto.

Fig. 2 is a top view of the heat shield alone.

The carburetor illustrated is of a well-known down-draft type including a mixture barrel 5 having a Venturi tube 6 traversed by a jet bar 7. The usual choke valve 8 and throttle valve 9 are provided at the inlet and outlet portions of the barrel. Adjacent the barrel is a constant level fuel chamber 10 enclosing a float H which acts on a needle valve I2 in inlet [3, for connection to the usual fuel pump (not shown), for maintaining a substantially uniform level of fuel in the bowl. The main fuel supply is through metering orifice element M and main nozzle passage I5 discharging through lateral openings IS in jet bar 7 into Venturi tube 6. Well known idling and accelerating pump systems (not shown) are also provided, as is customary.

The carburetor is mounted on the engine intake manifold, indicated at l8, and projects above the same. Heat from the manifold system radiates upwardly and that from the engine radiates sidewardly and upwardly toward the carburetor. In order to shield the carburetor from this heat, a deflector l9, conveniently of sheet metal with polished outer surface, is provided. This deflector, in the present instance, is in the shape of a cup or an inverted bell and is clamped between the main body casting 20 and heat insulating gasket 2! between said body 20 and the throttle .body casting 22. This shield or deflector completely surrounds the carburetor and, particularly, bowl l0, and also underlies the same so as to effectively deflect radiant heat therefrom.

The deflector is slightly spaced on all sides from the carburetor so that an insulating air cushion is rovided and is wholly open at the top to permit escape of heat from the carburetor.

I have found that by applying my novel heat deflector shield to a carburetor applied to an automotive engine, the fuel temperature in the constant level bowl is reduced as much as F., or sufiiciently to greatly reduce boiling in the fuel bowl and fuel passages of the carburetor. While a deflector with a polished outer surface works effectively, the part may be constructed itself of insulating material or may have an insulating wrapping or coating applied thereto.

The invention may be modified in these and other respects as will occur to those skilled in the art and the exclusive use of all modifications as come within the scope of the appended claim is contemplated.

I claim:

In an internal combustion engine, a fuel feed device including a fuel chamber, and an inverted bell-shaped deflector of sheet metal formed with an outwardly flaring upper marginal edge portion receiving said chamber but spaced therefrom, said deflector extending at least as high as said chamber and shielding said chamber from engine heat on all sides and from below, said deflector being wholly open at the top to permit the upward escape of heat from said device and chamber.

LEONARD D. BOYCE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,596,173 Goode Aug. 17, 1926 1,789,005 Larkin Jan. 13, 1931 FOREIGN PATENTS Number Country Date 880,587 France Jan. 4, 1943 

